Aromatic acylation with cyclic anhydride for plasticizer production

ABSTRACT

Provided is a process for making non-phthalate plasticizers, by acylating an aromatic compound with a succinic anhydride to form a keto-acid, and then esterifying the keto-acid with C 4 -C 13  OXO-alcohols to form a plasticizer compound. The aromatic rings of the aromatic compound may also be optionally hydrogenated.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application filed under 37 C.F.R.1.53(b) of parent application U.S. Ser. No. 12/840,715, the entirety ofwhich is hereby incorporated herein by reference, which claims priorityto U.S. Provisional Patent Application No. 61/284,789 filed on Dec. 24,2009, also herein incorporated by reference in its entirety.

FIELD

This disclosure is related to a potential route to non-phthalate,OXO-(di)ester plasticizers.

BACKGROUND

Plasticizers are incorporated into a resin (usually a plastic orelastomer) to increase the flexibility, workability, or distensibilityof the resin. The largest use of plasticizers is in the production of“plasticized” or flexible polyvinyl chloride (PVC) products. Typicaluses of plasticized PVC include films, sheets, tubing, coated fabrics,wire and cable insulation and jacketing, toys, flooring materials suchas vinyl sheet flooring or vinyl floor tiles, adhesives, sealants, inks,and medical products such as blood bags and tubing, and the like.

Other polymer systems that use small amounts of plasticizers includepolyvinyl butyral, acrylic polymers, nylon, polyolefins, polyurethanes,and certain fluoroplastics. Plasticizers can also be used with rubber(although often these materials fall under the definition of extendersfor rubber rather than plasticizers). A listing of the majorplasticizers and their compatibilities with different polymer systems isprovided in “Plasticizers,” A. D. Godwin, in Applied Polymer Science21st Century, edited by C. D. Craver and C. E. Carraher, Elsevier(2000); pp. 157-175.

Plasticizers can be characterized on the basis of their chemicalstructure. The most important chemical class of plasticizers is phthalicacid esters, which accounted for about 85% worldwide of PVC plasticizerusage in 2002. However, in the recent past there has been an effort todecrease the use of phthalate esters as plasticizers in PVC,particularly in end uses where the product contacts food, such as bottlecap liners and sealants, medical and food films, or for medicalexamination gloves, blood bags, and IV delivery systems, flexibletubing, or for toys, and the like. For these and most other uses ofplasticized polymer systems, however, a successful substitute forphthalate esters has heretofore not materialized.

One such suggested substitute for phthalates are esters based oncyclohexanoic acid. In the late 1990's and early 2000's, variouscompositions based on cyclohexanoate, cyclohexanedioates, andcyclohexanepolyoate esters were said to be useful for a range of goodsfrom semi-rigid to highly flexible materials. See, for instance, WO99/32427, WO 2004/046078, WO 2003/029339, WO 2004/046078, U.S. PatentPublication No. 2006-0247461, and U.S. Pat. No. 7,297,738.

Other suggested substitutes include esters based on benzoic acid (see,for instance, U.S. Pat. No. 6,740,254, and also co-pending,commonly-assigned, PCT Publication No. WO2009/118261A1, and polyketones,such as described in U.S. Pat. No. 6,777,514; and also co-pending,commonly-assigned, U.S. Patent Application Publication No. 2008-0242895A1. Epoxidized soybean oil, which has much longer alkyl groups (C₁₆ toC₁₈) has been tried as a plasticizer, but is generally used as a PVCstabilizer. Stabilizers are used in much lower concentrations thanplasticizers. Co-pending and commonly assigned U.S. patent applicationSer. No. 12/653,744, filed Dec. 17, 2009, discloses triglycerides with atotal carbon number of the triester groups between 20 and 25, producedby esterification of glycerol with a combination of acids derived fromthe hydroformylation and subsequent oxidation of C₃ to C₉ olefins,having excellent compatibility with a wide variety of resins and thatcan be made with a high throughput.

U.S. Pat. Nos. 1,909,092 and 2,233,513, both to Brunson and incorporatedherein by reference, disclose esters of aryl benzoic acids of theformula R—CO—R′—COOH, wherein R and R′ are aromatic nuclei, includingesters derived from saturated monohydric alcohols containing three ormore carbon atoms in the molecule, such as iso-propyl, butyl, isoamyl,beta-ethoxyethyl, beta-butoxyethyl, benzyl and cyclohexyl alcohols. Theesters are disclosed as useful as plasticizers for nitrocellulose.

U.S. Pat. No. 2,372,947 to Gresham, incorporated herein by reference,discloses polyvinyl halide compositions containing alkyl esters ofortho-benzoyl benzoic acid, wherein the ester group is a C₄ to C₁₆alkyl, such as butyl o-benzoyl benzoate, 2-ethylhexyl o-benzoylbenzoate, lauryl o-benzoyl benzoate, and cetyl o-benzoyl benzoate.

U.S. Pat. No. 3,110,724 to Woodbridge et al., incorporated herein byreference, discloses a process of reacting an aromatic anhydride withanother aromatic compound over a catalyst and esterifying the resultingintermediate with a polyalkylene glycol to form surfactants.

Co-pending and commonly owned U.S. Provisional Patent Application Ser.No. 61/227,116, filed Jul. 21, 2009, herein incorporated by reference,discloses the esterification of keto acids derived from the acylation ofaromatic compounds with cyclic anhydrides.

Thus what is needed is a method of making a general purposenon-phthalate plasticizer having and providing a plasticizer havingsuitable melting or chemical and thermal stability, pour point, glasstransition, increased compatibility, good performance and lowtemperature properties.

SUMMARY

In one aspect, the present application is directed to a process formaking non-phthalate plasticizers, comprising acylating an aromaticcompound with a succinic anhydride to form a keto-acid, and esterifyingthe keto-acid with C₄-C₁₃ OXO-alcohols to form a plasticizer compound.The aromatic compound may have one or multiple rings.

In a preferred embodiment, the aromatic compound is of the formula:

wherein R₁ is selected from the group consisting of H or C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether and wherein there may be 1 or2 R₁ groups present on the aromatic or saturated ring which may be thesame or different, and the plasticizer compound is of the formula:

wherein R₁ is as set forth above, R₂ is the alkyl residue of theOXO-alcohols, and R₃ is H or C₁-C₈ linear or branched alkyl group.

In another embodiment, the acylation is catalyzed by a heterogeneouscatalyst, a mixed metal oxide or a Lewis acid.

Preferably, the acylation is conducted using a stoichiometric amount ofAlCl₃.

The process can further comprise hydrogenating one or more of thearomatic rings of the aromatic compound.

In a preferred embodiment, the process can further comprisehydrogenating the keto-group(s) of the plasticizer compound to formalcohol groups, and esterifying the alcohol groups with C₄ to C₁₃ linearor OXO-acids to form plasticizer compounds of the formula:

wherein R₄ is the alkyl residue of said linear or OXO-acids. Anotherembodiment of the disclosure is directed to a plasticizer compound ofthe formula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether, and R₂ is the alkyl residueof C₄ to C₁₃ OXO-alcohols and wherein there may be 1 or 2 R₁ groupspresent on the aromatic or saturated ring which may be the same ordifferent. R₃ is H or C₁-C₈ linear or branched alkyl group.

Additionally, the present disclosure is directed to a plasticizercompound of the formula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether, wherein there may be 1 or 2R₁ groups present on the aromatic or saturated ring which may be thesame or different, R₂ is the alkyl residue of C₄ to C₁₃ OXO-alcohols, R₃is H or C₁-C₈ linear or branched alkyl group, and R₄ is the alkylresidue of C₄ to C₁₃ linear or OXO-acids.

In another embodiment, the present disclosure is directed to acomposition comprising a polymer and a plasticizer of the formula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether, wherein there may be 1 or 2R₁ groups present on the aromatic or saturated ring which may be thesame or different, R₂ is the alkyl residue of C₄ to C₁₃ OXO-alcohols,and R₃ is H or C₁-C₈ linear or branched alkyl group.

Conveniently, the composition contains a polymer selected from the groupconsisting of vinyl chloride resins, polyesters, polyurethanes,ethylene-vinyl acetate copolymer, rubbers, poly(meth)acrylics andcombinations thereof, preferably polyvinylchloride.

In another embodiment, the disclosure is directed to a compositioncomprising a polymer and a plasticizer of the formula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether wherein there may be 1 or 2R₁ groups present on the aromatic or saturated ring which may be thesame or different, R₂ is the alkyl residue of C₄-C₁₃ OXO-alcohols, R₃ isH or C₁-C₈ linear or branched alkyl group, and R₄ is the alkyl residueof C₄-C₁₃ linear or OXO-acids.

Preferably the polymer is selected from the group consisting of vinylchloride resins, polyesters, polyurethanes, ethylene-vinyl acetatecopolymer, rubbers, poly(meth)acrylics and combinations thereof, andmore preferably is polyvinylchloride.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing a comparison of the long term stabilityagainst hydrolysis of various plasticizers (DINP=diisononyl phthalate;C₉BPA=OXO—C₉ benzoyl propionate (Ex. 18); C₉BBA=OXO—C₉ benzoyl benzoate(Ex. 3).

DETAILED DESCRIPTION

All numerical values within the detailed description and the claimsherein are modified by “about” or “approximately” the indicated value,and take into account experimental error and variations that would beexpected by a person having ordinary skill in the art.

There is an increased interest in developing new plasticizers that arenon-phthalates and which possess good plasticizer performancecharacteristics but are still competitive economically. The presentdisclosure is directed towards non-phthalate, OXO-(di)ester plasticizersthat can be made from low cost feeds and employ fewer manufacturingsteps in order to meet economic targets. The process for making thenon-phthalate plasticizers disclosed herein is to produce a single ormulti ring aromatic acid, made from single or multi ring aromaticmolecule acylation with a cyclic anhydride, followed by esterificationof the acid with OXO C₄-C₁₃ alcohols. Two additional steps may also beoptionally utilized for fine tuning plasticizer compatibility,volatility, or stability, which are: i) converting the carbonyl group toan alcohol group using hydrogenation technology and esterifying thealcohol with OXO C₄-C₁₃ acids; and ii) hydrogenating one or more of theunsaturated aromatic rings.

Branched aldehydes can be produced by hydroformylation of C₃-C₁₂olefins; in turn, some of these olefins have been produced by propyleneand/or butene oligomerization over solid phosphoric acid or zeolitecatalysts. The resulting C₄-C₁₃ aldehydes can then be recovered from thecrude hydroformylation product stream by fractionation to removeunreacted olefins. These C₄-C₁₃ aldehydes can then hydrogenated toalcohols (OXO-alcohols) or oxidized to acids (OXO-acids). Single carbonnumber acids or alcohols can be used in the esterification of thearomatic acids described above, or differing carbon numbers can be usedto optimize product cost and performance requirements. The “OXO”technology will provide cost advantaged alcohols and acids. Otheroptions are considered, such as hydroformylation of C₄-olefins toC₅-aldehydes, followed by hydrogenation to C₅-alcohols, or aldehydedimerization followed by hydrogenation or oxidation to C₁₀-alcohols oracids.

The resulting C₄-C₁₃ OXO-alcohols (and acids) may be used individually,or together in mixtures to make mixed carbon number materials to makeesters for use as plasticizers. The mixing of carbon numbers and levelsof branching may be required to achieve the desired compatibility withPVC for the respective aromatic acid used for the polar end of theplasticizer, and to meet other plasticizer performance properties. Thefeed can be propylene, butenes, pentenes, hexenes, heptenes, octenes ornonenes as the starting olefins. The selected from C₄-C₁₃ OXO-acids oralcohols have an average branching of from about 0.2 to about 4.0branches per molecule. Average branching is determined by NMR. Theaverage branching of the alkyl groups incorporated into the plasticizersas the residues of the OXO-acid or alcohol reagents may range from 0.2to 4.0, or 0.5 to 3.5, or 1.0 to 3.0, or 1.5 to 2.5 branches perresidue.

An “OXO-ester” is a compound having at least one functional ester moietywithin its structure derived from esterification of either an acid oralcohol compound with an OXO-alcohol or OXO-acid, respectively.

An “OXO-alcohol” is an organic alcohol, or mixture of organic alcohols,which is prepared by hydroformylating an olefin, followed byhydrogenation to form the alcohols. Typically, the olefin is formed bylight olefin oligomerization over heterogeneous acid catalysts, whicholefins are readily available from refinery processing operations. Thereaction results in mixtures of longer-chain, branched olefins, whichsubsequently form longer chain, branched alcohols, as described in U.S.Pat. No. 6,274,756, incorporated herein by reference in its entirety.

An “OXO-acid” is an organic acid, or mixture of organic acids, which isprepared by hydroformylating an olefin, followed by oxidation to formthe acids. Typically, the olefin is formed by light olefinoligomerization over heterogeneous acid catalysts, which olefins arereadily available from refinery processing operations. The reactionresults in mixtures of longer-chain, branched olefins, whichsubsequently form longer-chain, branched acids.

Alternatively, the OXO-acids or OXO-alcohols can be prepared by aldolcondensation of shorter-chain aldehydes to form longer chain aldehydes,as described in U.S. Pat. No. 6,274,756, followed by oxidation orhydrogenation to form the OXO-acids or OXO-alcohols, respectively.

Tables 1A and 1B below provide branching characteristics for typicalOXO-alcohols and OXO-acids, measured by ¹³C NMR.

TABLE 1A ¹³C NMR Branching Characteristics of Typical OXO-Alcohols. % ofTotal Pendant Pendant OXO- Avg. α-Carbons β-Branches Methyls MethylsEthyls Alcohol Carbon No. w/Branches^(a) per Molecule^(b) perMolecule^(c) per Molecule^(d) per Molecule C₄ ^(e) 4.0 0 0.35 1.35 0.350 C₅ ^(f) 5.0 0 0.30 1.35 0.35 0 C₆ — — — — — — C₇ 7.3 0 0.15 1.96 0.990.04 C₈ 8.6 0 0.09 3.0 1.5 — C₉ 9.66 0 0.09 3.4 — — C₁₀ 10.2 0 0.16 3.2— — C₁₂ 12.2 0 — 4.8 — — C₁₃ 13.1 0 — 4.4 — — — Data not available.^(a)-COH carbon. ^(b)Branches at the-CCH₂OH carbon. ^(c)This valuecounts all methyl groups, including C₁ branches, chain end methyls, andmethyl cndgroups on C₂+ branches. ^(d)C₁ branches only. ^(e)Calculatedvalues based on an assumed molar isomeric distribution of 65% n-butanoland 35% isobutanol (2-methylpentanol). ^(f)Calculated values based on anassumed molar isomeric distribution of 65% n-pentanol, 30%2-methylbutanol, and 5% 3-methylbutanol.

TABLE 1B ¹³C NMR Branching Characteristics of Typical OXO-Acids. AverageOXO- Carbon Pendant Total Pendant % Carbonyls α Acid No. Methyls^(a)Methyls^(b) Ethyls to Branch^(c) C₄ ^(d) 4.0 0.35  1.35 0 35 C₅ ^(e) 5.00.35  1.35 0 30 C₆ — — — — — C₇ 6.88-7.92 0.98-1.27 1.94-2.48 0.16-0.2611.3-16.4 C₈ 8.1-8.3 — 2.7 — 12-15 C₉ 9.4 — n/a — 12 C₁₀ 10.2  — n/a —12 C₁₂ — — — — — C₁₃ 12.5  — 4.4 — 11 — Data not available. ^(a)C₁Branches only. ^(b)Includes methyls on all branch lengths and chain endmethyls. ^(c)The “alpha” position in the acid nomenclature used here isequivalent to the alcohol “beta” carbon in Table 1A. ^(d)Calculatedvalues based on an assumed molar isomeric distribution of 65% n-butanoicacid and 35% isobutanoic acid (2-methylpentanoic acid). ^(e)Calculatedvalues based on an assumed molar isomeric distribution of 65%n-pentanoic acid, 30% 2-methylbutanoic acid, and 5% 3-methylbutanoicacid.

“Hydroformylating” or “hydroformylation” is the process of reacting acompound having at least one carbon-carbon double bond (an olefin) in anatmosphere of carbon monoxide and hydrogen over a cobalt or rhodiumcatalyst, which results in addition of at least one aldehyde moiety tothe underlying compound. U.S. Pat. No. 6,482,972, which is incorporatedherein by reference in its entirety, describes the hydroformylation(OXO) process.

“Hydrogenating” or “hydrogenation” is addition of hydrogen (H₂) to adouble-bonded functional site of a molecule, such as in the presentcase, addition of hydrogen to the ketone functionality of theplasticizer to give an alcohol functionality, or to the aldehydemoieties of an OXO-aldehyde, to form the corresponding alcohol.Hydrogenation may also be the addition of hydrogen (H₂) to one or morearomatic rings of the plasticizer or a precursor thereof, to form asaturated cyclic structure. Conditions for hydrogenation are well knownin the art and include, but are not limited to temperatures of 0-300°C., pressures of 1-500 atmospheres, and the presence of homogeneous orheterogeneous hydrogenation catalysts such as Pt/C, Pt/Al₂O₃ orPd/Al₂O₃.

“Esterifying” or “esterification” is reaction of a carboxylic acidmoiety with an organic alcohol moiety to form an ester linkage.Esterification conditions are well-known in the art and include, but arenot limited to, temperatures of 0-300° C., and the presence or absenceof homogeneous or heterogeneous esterification catalysts such as Lewisor Brønsted acid catalysts.

In general, for every polymer to be plasticized, a plasticizer isrequired with the correct balance of solvating properties, volatilityand viscosity to have acceptable plasticizer compatibility with theresin. In particular, if the 20° C. kinematic viscosity is higher than150 mm²/sec as measured by the appropriate ASTM test, or alternately ifthe 20° C. cone-and-plate viscosity is higher than 150 cP, this willaffect the plasticizer processability during formulation, and mayrequire heating the plasticizer to ensure good transfer during storageand mixing of the polymer and the plasticizer. Volatility is also a verycritical factor which affects the long-term plasticizer formulationstability. Higher volatility plasticizers can migrate from the plasticresin matrix and cause damage to the article. The plasticizer volatilityin a resin matrix can be roughly predicted by neat plasticizer weightloss at 220° C. using Thermogravimetric Analysis.

The present disclosure discloses unexpected structure-propertyrelationships arising from the addition of specific substituents to thearomatic ring of the aromatic acid fragment of the plasticizer molecule.These manipulations allow for the preparation of novel ketoesterplasticizers having improved volatility-viscosity balances.

One potential route to non-phthalate plasticizers is by acylating analkyl aromatic acid with a succinic anhydride of the general structure

wherein R₃ can be H or C₁-C₈ alkyl, (ex: methylsuccinic anhydride,isopropylsuccinic anhydride, n-butylsuccinic anhydride, n-octylsuccinicanhydride) followed by esterification of the free acid group with anOXO-alcohol. When there are two R₃ groups present on the anhydride, theymay also form a fused C₆ aromatic ring, as in phthalic anhydride.Non-limiting exemplary aromatic compounds for acylation are as follows:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether and wherein there may be 1 or2 R₁ groups present on the aromatic or saturated ring which may be thesame or different.

The general reaction mechanism is illustrated as follows:

In the above structure, R₁ is selected from the group consisting of H,C₁-C₉ linear or branched alkyl, cycloalkyl, or C₁-C₄ ether, whereinthere may be 1 or 2 R₁ groups present on the aromatic or saturated ringwhich may be the same different, R₂ is the alkyl residue of C₄-C₁₃OXO-alcohols, and R₃ is H or a C₁-C₈ linear or branched alkyl group.

Following the esterification step with the OXO-alcohol (or, alternately,following the acylation step with the cyclic anhydride), one or more ofthe aromatic rings of the aromatic compounds depicted above may also behydrogenated using typical hydrogenation catalysts known in the art, andin particular the platinum group metals, such as palladium, ruthenium,or combinations thereof on a silica, carbon, or alumina support at ametals loading level on the support of 0.1-10, or 0.5-7, or 1-5 wt. %.The hydrogenation conditions may be at a temperature of 80-300, or100-280, or 150-250° C. at a pressure of 100-3000, or 500-2500, or1000-2000 psig. Hence, the plasticizer compound depicted above may beunsaturated, partially saturated, or fully saturated depending uponhydrogenation of the one or more aromatic rings of the compound. Thegeneral mechanism is illustrated as follows:

An extra two steps may then be optionally used to convert the carbonylgroup of the above products to an alcohol group using hydrogenationtechnology, and then the alcohol may be esterified per the schematicbelow:

The general reaction mechanism above as broadened to include both singleand multi-ring aromatic substrates is illustrated as follows, whereinthe OXO-diester can be formed by hydrogenating the remaining carbonylgroup to form an hydroxyl moiety, followed by esterification with anOXO-acid.

In the above structure, R₁ is selected from the group consisting of H,C₁-C₉ linear or branched alkyl, cycloalkyl, or C₁-C₄ ether wherein theremay be 1 or 2 R₁ groups present on the aromatic or saturated ring whichmay be the same or different, R₂ is the alkyl residue of C₄-C₁₃OXO-alcohols, R₃ is H or C₁-C₈ linear or branched alkyl group, and R₄ isthe alkyl residue of C₄-C₁₃ linear or OXO-acids.

Following (or, alternately, preceding) the esterification step with theOXO-acid, one or more of the aromatic rings of the aromatic compoundsdepicted above may also be hydrogenated using typical hydrogenationcatalysts known in the art, and in particular the platinum group metals,such as palladium, ruthenium, or combinations thereof on a silica,carbon, or alumina support at a metals loading level on the support of0.1-10, or 0.5-7, or 1-5 wt. %. The hydrogenation conditions may be at atemperature of 80-300, or 100-280, or 150-250° C. at a pressure of100-3000, or 500-2500, or 1000-2000 psig. Hence, the plasticizercompound depicted above may be unsaturated, partially saturated, orfully saturated depending upon hydrogenation of the one or more aromaticrings of the compound. The general mechanism is illustrated as follows:

The same acylation, hydrogenation, and esterification chemistry that isapplied hereinabove could be also used for already partiallyhydrogenated multi-ring molecules, and with separate or simultaneoushydrogenation steps (for example, the overall reaction scheme shownbelow):

As discussed above, the resulting C₄-C₁₃ acids or alcohols can be usedindividually or together in acid mixtures or alcohol mixtures havingdifferent chain lengths, to make mixed carbon number esters to be usedas plasticizers. This mixing of carbon numbers and levels of branchingcan be advantageous to achieve the desired compatibility with PVC forthe respective polyol or polyacid used for the polar moiety end of theplasticizer, and to meet other plasticizer performance properties. Theselected from C₄-C₁₃ acids or alcohols have an average branching of fromabout 0.2 to about 4.0 branches per molecule. Average branching isdetermined by NMR. The average branching of the alkyl groupsincorporated into the plasticizers as the residues of the acid oralcohol reagents ranges from 0.2-4.0, or 0.5-3.5, or 1.0-3.0, or 1.5-2.5branches per residue. The starting olefin feed can be C₃═, butenes, C₅═,C₆═, C₇═, C₈═ or C₉═.

We have found that when C₄-C₁₃ OXO-alcohols, OXO-acids or linear acidsare used as reactants for the esterification reactions described above,the resulting OXO-esters are in the form of relatively high-boilingliquids (having low volatility), which are readily incorporated intopolymer formulations as plasticizers.

EXAMPLES General Procedure for Esterification

Into a 4-necked 500 mL round bottom flask equipped with an air stirrer,thermometer, N₂ inductor, Dean-Stark trap and chilled water cooledcondenser were added the amounts of carboxylic acid (commerciallypurchased benzoyl and alkylbenzoyl benzoic acids) and alcohol specifiedin the following Examples. The Dean-Stark trap was filled withadditional alcohol. Toluene and/or xylenes were optionally also added tocontrol the temperature and to provide adequate reflux for waterremoval. The contents of the flask were stirred at the specifiedtemperature for the specified time and water was collected in theDean-Stark trap. The crude reaction mixture was optionally washed with a3 wt % NaOH solution to remove residual acid prior to vacuumdistillation to remove excess alcohol, and/or treated with 2 wt %decolorizing charcoal by stirring at room temperature for 2 hours,followed by double filtration to remove the charcoal. In some examplesthe product (rather than only residual alcohol) was distilled overhead.The specific reaction conditions and product workup are indicated in thefollowing tables and examples. The general esterification reaction isshown in Equation 1, below. The product purity was evaluated by gaschromatography (GC) analysis, conducted using a Hewlett-Packard 5890 GCequipped with a HP6890 autosampler, a HP flame-ionization detector, anda J&W Scientific DB-1 30 meter column (0.32 micrometer inner diameter, 1micron film thickness, 100% dimethylpolysiloxane coating). The initialoven temperature was 60° C.; injector temperature 290° C.; detectortemperature 300° C.; the temperature ramp rate from 60-300° C. was 10°C./minute with a hold at 300° C. for 14 minutes. The calculated %'sreported for products were obtained from peak area, with an FID detectoruncorrected for response factors.

Examples 1-8 demonstrate esterification of benzoylbenzoic andtoluoylbenzoic acids with different alcohols, the results of which areset forth in Table 2, below (where R is equivalent to R₁ as describedpreviously).

TABLE 2 Acid Conv. %, Carboxylic acid Alcohol Rxn Temp (° C.), Solvent,Product Purity Ex., R (grams, moles)^(a) (grams, moles)^(b) Time (h)Workup^(c) (%) 1, H 2-BenzoylBz 1.86:1 Hexanol/2- 175, 8 None, A 99.2,99.8 (191.8, 0.85) methylpentanol (173.3/1.696) 2, H 2-BenzoylBz2-Ethylhexanol 210, 4 None, A 99.0, 99.6 (158.3, 0.7) (182.23, 1.4) 3, H2-BenzoylBz OXO-C₉ 220, 8 None, A 93.8, 99.4 (155.5, 0.6874) (198.82,1.3748) 4, H 2-BenzoylBz Nonanol 220, 5 None, A 97.8, 99.6 (118.9,0.526) (151.64, 1.05) 5, Me 2-(4-Toluoyl)Bz 1.86:1 Pentanol/2- 150, 9None, B 99.0, 99.2 (155.0, 0.6464) methylbutanol (113.9, 1.291) 6, Me2-(4-Toluoyl)Bz 1.843:1 Hexanol/2-   170, 5.5 None, B NA, 98.7 (150.0,0.625) methylpentanol (128, 1.25) 7, Me 2-(4-Toluoyl)Bz 2-Ethylhexanol210, 6 None, B 95.6, 97.4 (116.25, 0.5) (126.21, 0.9696) 8, Me2-(4-Toluoyl)Bz OXO-C₉ 220, 4 None, B 90.1, 99.6 (115.1, 0.48) (138.6,0.96) ^(a)Bz = Benzoic acid ^(b)Ratios of acids are molar ratios. ^(c)A= Distilled off excess alcohol only; B = distilled product

Table 3 (where R is equivalent to R₁ as described previously and R′ isequivalent to R₂ as described previously) below provides neat propertiesof the benzoyl benzoic and toluoyl benzoic acid esters prepared inExamples 1-8. Thermogravimetric Analysis (TGA) was conducted using a TAInstruments AutoTGA 2950HR instrument (25-600° C., 10° C./min, under 60cc N₂/min flow through furnace and 40 cc N₂/min flow through balance;sample size 10-20 mg). Differential Scanning Calorimetry (DSC) was alsoperformed, using a TA Instruments 2920 calorimeter fitted with a liquidN₂ cooling accessory. Samples were loaded at room temperature and cooledto −130° C. at 10° C./min and analyzed on heating to 75° C. at a rate of10° C./min. T_(g)s given are midpoints of the second heats (unless onlyone heat cycle was performed, in which case the first heat T_(g), whichis typically in very close agreement, is given). Kinematic Viscosity(KV) was measured at 20° C. according to ASTM D-445-20, the disclosureof which is incorporated herein by reference, or as footnoted in theTables.

TABLE 3 TGA TGA TGA TGA 1% 5% 10% Wt Loss, DSC KV Wt Loss Wt Loss WtLoss 220° C. T_(g) (20° C., Ex., R, R’ (° C.) (° C.) (° C.) (%) (° C.)mm²/sec) 1, H, C₆ 155.0 187.5 202.3 21.3 −60^(a) 309.69 2, H, 2EH^(f)167.1 196.7 211.1 14.9 −61.3 451.60 3, H, C₉ 173.3 204.3 219.0 10.4−58.1 434.47 4, H, n-C₉ 178.4 208.7 223.7  8.5 −68.9^(b) 184.6 5, Me, C₅157.8 189.9 204.8 19.4 −51.4^(c) 784.93 6, Me, C₆ 161.3 194.4 210.5 14.7−54.4 556.6 7, Me, EH^(f) 171.0 202.9 217.6 11.1 −56.8^(e) —^(d) 8, Me,C₉ 177.4 214.1 229.5  6.5 −53.9 775.38 — Data not taken. ^(a)2nd smallapparent T_(g), 36.3° C. ^(b)Small melting transition, 54.7° C.^(c)Small unidentified exotherm in both 1^(st) and 2^(nd) heats, ~−18 C.^(d)Sample was noted as a mixture of solid and liquid. ^(e)2nd smallpotential T_(g), 50.4° C.; small melting transition, 22.5° C.;^(f)2-ethylhexyl.

The data in Table 3 show that, in order to decrease volatility, heavyalcohols had to be used which at the same time adversely affectviscosity. The addition of a methyl group to the benzene ring resultedin higher viscosity than without a methyl group. A different group(—CH₂CH₂—) separating the keto and ester functionalities was used inorder to modify the volatility/viscosity balance. The synthesis ofbenzoyl and alkylbenzoyl propionic acids via acylation is shown inEquation 2 (where R is equivalent to R₁ as described previously). Thoseof skill in the art will recognize that any suitable acylation catalyst,such as a heterogeneous catalyst, a mixed metal oxide or a Lewis acidsuch as a homogeneous Lewis acid, such as AlCl₃, can be used to catalyzethe reaction.

Representative Procedure for the Synthesis of Aromatic Keto Acids:

99.5 g (0.94 mole) o-xylene, 31.3 g (0.31 mole), succinic anhydride, and190 mL nitrobenzene were placed into a 1 liter round bottom flask fittedwith an addition funnel, thermometer, mechanical stirrer and nitrogenpurge. The flask was cooled to 0° C., then 83.4 g (0.63 mole) ofaluminum trichloride, dissolved in 350 mL nitrobenzene, was addeddropwise maintaining the temperature at 0° C. After addition, thesolution was stirred overnight and the temperature was allowed to reachroom temperature. The solution was poured into a 2 liter beakercontaining 120 mL concentrated aqueous HCl, 500 mL water, and 1000 gice. The mixture was extracted twice with 1000 mL ethyl ether. The etherlayers were combined and washed with 500 mL water, then extracted twicewith 500 mL 5% aqueous potassium hydroxide. The aqueous layers werecombined and washed with 500 mL ether. The aqueous layer was acidifiedwith 100 mL concentrated aqueous HCl to precipitate the product. Theproduct was collected by filtration and washed with 500 mL water. Theproduct was dissolved in chloroform and the solution was dried overmagnesium sulfate, filtered, and stripped of chloroform under vacuum togive 61.4 g (95.4% yield) of crude product. The product was crystallizedfrom benzene giving a weight of 59.9 g.

A number of aromatic keto acids of the general structure shown inEquation 2 were prepared by acylation of alkylaromatics with succinicanhydride, using an aluminum trichloride reagent (rather than aheterogeneous catalyst). The following procedure is representative. Thesyntheses of aromatic keto acids prepared by this method are summarizedin Table 4 (Examples 9-16), where R is equivalent to R₁ as describedpreviously.

TABLE 4 Crude Weight after Moles aromatic, weight (g) crystallizationEx. No. R anhydride, AlCl₃ (yield, %) (g) 9 Sec-butyl 0.94, 0.31, 0.6371.3 (91.7) 59.1 10 ethyl 0.94, 0.31, 0.63 57.6 (89.5) 33.5 11 n-nonyl0.49, 0.16, 0.33 42.2 (88.5) NA 12 n-hexyl 0.94, 0.31, 0.63 52.0 (63.5)NA 13 o-dimethyl 0.94, 0.31, 0.63 61.4 (95.4) 59.9 14 m-dimethyl 0.75,0.25, 0.50 48.0 (93.1) 28.2 15 p-dimethyl 0.94, 0.31, 0.63 58.5 (90.9)49.6 16 cyclohexyl 0.94, 0.31, 0.63 72.5 (89.3) 67.6 NA = data notavailable.

The following examples illustrate the synthesis and properties ofketoesters prepared by esterification of arylpropionic acids, includingthe acids prepared in Table 4 and others from commercial sources. Thegeneral esterification procedure already described was used. Tables 5and 6 (where R is equivalent to R₁ as described previously and in theseinstances is H, and R′ is equivalent to R₂ as described previously)summarize the synthesis and performance of esters made frombenzoylpropionic acid (which may be derived from benzene acylation withsuccinic anhydride) with and various alcohols as shown in Equation 3,below, where R′ is equivalent to R₂ as described previously.

TABLE 5 Carboxylic acid Alcohol Rxn Temp Solvent, Acid Conv. %, Ex. No.,R (grams, moles)^(a) (grams, moles) (° C.), Time (h) Workup^(b) ProductPurity (%) 17, H 3-BenzoylPr 2-ethyl-1-hexanol 220, 6 None, B 97.6, 96.6(52.5, 0.295) (76.7, 0.59) 18, H 3-BenzoylPr OXO-C₉ 220, 5 None, A 98.4,99.6 (147.7, 0.829) (239.7, 1.66) 19, H 3-BenzoylPr OXO-C₁₃ 205, 3Xylenes,^(c) NA, 99.4 (189.4, 1.063) (425.6, 2.13) A + C 20, H3-BenzoylPr Nonanol 220, 6 None, B 95.7, 96.7 (43.2, 0.242) (85.4,0.592) ^(a)Pr = Propionic ^(b)A = Distilled off excess alcohol only; B =distilled product; C = treated alkyl residue with charcoal. ^(c)44.6 g,0.42 moles.

TABLE 6 TGA TGA TGA TGA 1% 5% 10% Wt Loss, DSC KV Ex. No., Wt Loss WtLoss Wt Loss 220° C. T_(g) (20° C., (R, R’) (° C.) (° C.) (° C.) (%) (°C.) mm²/sec) 17, H, 2EH 135.3 169.4 184.3 43.9 −82.4^(a) 24.88 18, H, C₉149.6 182.1 196.8 27.0 −77.4 34.79 19, H, C₁₃ 169.7 202.7 217.6 11.1−70.9 75.62 20, H, n-C₉ 143.5 187.0 202.8 20.6 None^(b) 26.1 DINP 184.6215.2 228.5  6.4 −79.1 96.81 DINP = diisononyl phthalate; 2EH =2-ethylhexyl. ^(a)Small potential melting transitions at −20.8 and 54.1C. ^(b)Strong, narrow melting transition, 26.0° C.

The data in Table 6 show that the ester made from 2-ethylhexanol (2EH)is a very volatile product. Replacing the 2EH chain with an OXO—C₉ chaindramatically lowers the volatility of the ester and affects theviscosity. Using a heavier alcohol (C₁₃) resulted in a much lowervolatility and still gives a viscosity lower than that for DINP. Linearalcohols (e.g., n-nonanol) show better volatility and viscosity thanOXO-branched alcohols with the same carbon number.

Another approach for decreasing volatility is to use alkylated aromaticgroups to increase molecular weight, which affects volatility.Therefore, different esters were made using aromatic keto acids bearinga methyl group (this acid may be made from toluene acylation withsuccinic anhydride) as shown in Equation 4, below (where R′ isequivalent to R₂ as described previously).

Examples 21-24 in Table 7 (where R is equivalent to R₁ as describedpreviously) demonstrate esterification of methylbenzoylpropionic acidwith different alcohols. The volatility, viscosity, and glass transitionproperties of the neat plasticizers prepared in Examples 21-24 are setforth in Table 8 (where R is equivalent to R₁, and R′ is equivalent toR₂, as described previously), below.

TABLE 7 Acid Conv. %, Carboxylic acid Alcohol Rxn Temp (° C.), Solvent,Product Purity Ex. No., R (grams, moles)^(a) (grams, moles)^(d) Time (h)Workup^(b) (%) 21, Me 3-(4-Methyl- 65:35 hexanol/2- 203-210, 5   Non, B92.5, 96.4 benzoylPr methylpentanol (41.4, 0.22) (28.6, 0.15) 22, Me3-(4-Methyl- 2-ethyl-1-hexanol 217, 7 None, B 97.7, 96.0 benzoylPr(94.1, 0.722) (69.4, 0.3612) 23, Me 3-(4-Methyl- OXO-C₉ 220, 3 None, NA,99.9 benzoylPr (88.3, 0.612) A + C (59.0, 0.3104) 24, Me 3-(4-Methyl-OXO-C₁₃ 205, 3 Xylenes^(c), B 98.4, 98.0 benzoylPr (150.6, 0.75) (72.3,0.38) NA = data not available. ^(a)Pr = Propionic ^(b)A = Distilled offexcess alcohol only; B = distilled product; C = treated alkyl residuewith charcoal. ^(c)35.2 g, 0.33 moles. ^(d)Ratios of alcohols given aremolar ratios.

TABLE 8 TGA TGA TGA TGA 1% 5% 10% Wt Loss, DSC KV Ex. No., Wt Loss WtLoss Wt Loss 220° C. T_(g) (20° C., (R, R’) (° C.) (° C.) (° C.) (%) (°C.) mm²/sec) 21, Me, C₆ 136.1 1.67.4 182.8 42.8 −79.1^(a) 24.15 22, Me,2EH 140.7 182.7 198.1 25.4 −78.9^(b) 34.88 23, Me, C₉ 158.5 191.9 208.016.4 −74.2 45.26 24, Me, C₁₃ 152.0 203.9 222.9  8.9 −68.5 96.52 — = Datanot taken. 2EH = 2-ethylhexyl. ^(a)The DSC showed a large exotherm at−33.4° C. and a large endotherm at −1.7° C. in both the first and secondheats. ^(b)Potential small melting transitions, −35.1 and 50.6° C. (mayrepresent instrument problems).

The data in Table 8 show that when a C₁₃ alcohol and3-(4-methylbenzyl)propionic acid were used to synthesize the ketoesterplasticizer, the viscosity and the volatility were close to those forthe commercial general purpose plasticizer DINP. However, this willpractically limit the use of this plasticizer platform to the C₁₃alcohol derivative. Therefore, in order to design a better plasticizerstructure in which other OXO-alcohols can be used. Thedi-methyl-substituted (Me₂) alkyl aromatic acids shown in Equation 5(where R is equivalent to R₁ as described previously) were used toprepare related keto esters, as disclosed in Table 9 (where R isequivalent to R₁ as described previously), below. The volatility,viscosity, and glass transition properties of the neat plasticizersprepared in Examples 25-30 are set forth in Table 10 (where R isequivalent to R₁, and R′ is equivalent to R₂, as described previously),below.

TABLE 9 Acid Conv. Carboxylic acid Alcohol Rxn Temp (° C.), Solvent (g,mol), %, Product Ex. No., R (grams, moles) (grams, moles) Time (h)Workup^(a) Purity (%) 25, Me₂ 4-(2,4- OXO-C₉ 150, 11 Xylenes 94.5, 98.0dimethylphenyl)-4- (29.5, 0.204) (55, 0.52), A OXO-butanoic (21.03,0.102) 26, Me₂ 4-(2,4- OXO-C₁₀ 122, 18 Toluene 89.0, 99.5dimethylphenyl)-4- (19.06, 0.1203) (55, 0.597), A + B OXO-butanoic(12.4, 0.0602) 27, Me₂ 4-(3,4- OXO-C₉ 162, 13 Toluene 97.1, 98.6dimethylphenyl)-4- (108.2, 0.75) (50, 0.542), A OXO-butanoic (50.4,0.25) 28, Me₂ 4-(3,5- OXO-C₉ 150, 11 Toluene 97.2, 99.5dimethylphenyl)-4- (58.3, 0.404) (50, 0.542), A OXO-butanoic (27.6,0.14) 29, Me₂ 4-(2,5- OXO-C₉ 175, 13 Toluene 97.8, 99.2dimethylphenyl)-4- (99.2, 0.69) (52.3, 0.57), A OXO-butanoic (47.2,0.23) 30, Et 4-(4-ethylphenyl)-4- OXO-C₉ 170, 9  Toluene 99.6, 99.2OXO-butanoic (117.2, 0.812) (72.0, 0.781), C (33.2, 0.1624) ^(a)A =Washed with aqueous 3% NaOH, then water, then concentrated bydistillation; B = Dried over MgSO₄; C = Distilled away excess alcoholand treated alkyl residue with decolorizing charcoal.

TABLE 10 TGA TGA TGA TGA 1% 5% 10% Wt Loss, DSC KV Ex. No., Wt Loss WtLoss Wt Loss 220° C. T_(g) (20° C., (R, R’) (° C.) (° C.) (° C.) (%) (°C.) mm²/sec) 25, 2Me, C₉ 156.6 191.8 207.2 17.2 −74.6 39.72 26, 2Me, C₁₀169.2 200.6 215.5 12:2 −74.1 (51.33)^(a) 27, 2Me, C₉ 165.6 201.8 217.211.2 −69.6 (80.55)^(a) 28, 2Me, C₉ 161.8 193.8 209.1 15.8 −73.9 (41)^(a)29, 2Me, C₉ 159.1 192.5 207.6 17.0 −74.0 (44.4)^(a) 30, Et, C₉ 166.8200.2 215.7 11.9 −78.9 (39.1)^(a) — = Data not taken. ^(a)Cone-and-plateviscosity measurement in centiPoise (cP) taken using an Anton Paar (25mm) viscometer (sample, size ~0.1 mL); KV not taken.

The data in Table 10 show that indeed, addition of another methyl groupto the aromatic ring resulted in a decrease in the volatility using C₉alcohols compared to the toluoylpropionic acid ester plasticizers; atthe same time, viscosity remains below DINP viscosity. For comparison(two methyl groups vs one ethyl group), the C₉ ester of the ketoacidanalogous to the product of ethylbenzene acylation with succinicanhydride was prepared and evaluated. The data shows that the volatilityis similar to the analogous ester which would be derived from acylationof o-xylene, but the viscosity is much lower. The viscosity of theethyl-substituted ester is similar to the viscosity of the ester whichhas two methyl groups at the meta and para positions to the acylfunctionality. These data indicate that a mixed acylation feed of C₈alkylaromatics could be used to prepare a plasticizer, which would bemuch cheaper than using pure C₈ alkylaromatic isomers.

Further improvement on the plasticizers made using this approach wasperformed by using other alkyl substituents with more than 3 carbons anda methoxy substituent (equation 6, where R is equivalent to R₁, and R′is equivalent to R₂, as described previously). Data are summarized inTables 11 and 12 (having similar equivalencies for R and R′).

TABLE 11 Acid Conv. Carboxylic acid Alcohol Rxn Temp Solvent (g, mol),%, Product Ex. No., R (grams, moles)^(a) (grams, moles) (° C.), Time (h)Workup^(b) Purity (%) 31, t-Bu 4-(4-t-butylphenyl)-4- OXO-C₉ 150, 5 Xylenes 95.2, 95.1 OXO-butanoic (45.7, 0.317) (50, 0.47), A (37.1,0.1583) 32, t-Bu 4-(4-t-butylphenyl)-4- OXO-C₁₀ 150, 3  Xylenes 92.3,98.1 OXO-butanoic (2.9, 0.164) (44.63, 0.42), A (12.8, 0.055) 33, s-Bu4-(4-sec- OXO-C₉ 135, 24 Toluene 98.6, 97.6 butylphenyl)-4-OXO- (56.6,0.392) (42, 0.456), A butanoic (30.3, 0.131) 34, n-Hx4-(4-n-hexyl-phenyl)- OXO-C₉ 160, 10 Toluene 97.8, 97.6 4-OXO-butanoic(87.0, 0.60) (66.7, 0.72), B (52.0, 0.20) 35, Cy 4-(cyclo- OXO-C₉ 141,16 Xylenes 92.7, 94.5 hexylbenzyl)Pr (12.0, 0.0829) (35, 0.33), A(10.78, 0.0415) 35a, Cy 4-(cyclo- OXO-C₉ 158, 7  Xylene 89.7, 97.4hexylbenzyl)Pr (53.9, 0.373) (73.5, 0.693), B (32.3, 0.124) 36, n-Non4-(4-n-nonyl-phenyl)- OXO-C₉ 160, 11 Toluene 97.5, 96.5 4-OXO-butanoic(61.9, 0.429) (80.4, 0.87), A (43.2, 0.143) 37, O—Me 4-(4-methoxy-OXO-C₉ 158, 4  Xylenes 92.4, 98.7 benzoyl)Pr (47.9, 0.332) (84.8,0.798), A (34.6, 0.166) Pr = Propionic. Cy = cyclohexyl. ^(b)A = Washedwith aqueous 3% NaOH, then water, then concentrated by distillation; B =Distilled away excess alcohol.

TABLE 12 TGA TGA TGA TGA 1% 5% 10% Wt Loss, DSC KV Ex. No., Wt Loss WtLoss Wt Loss 220° C. T_(g) (20° C., (R, R’) (° C.) (° C.) (° C.) (%) (°C.) mm²/sec) 31, t-Bu, C₉ 147.0 206.8 223.7 8.5 −67.4 130.79 32, t-Bu,C₁₀ 171.8 209 225.0 8.0 −65.0 (156.6)^(a) 33, s-Bu, C₉ 175.4 210.2 226.07.7 −75.0  (87.2)^(a) 34, n-Hx, C₉ 200.1 232.4 248.2 2.8 −81.8^(b) (66.1)^(a) 35, Cy, C₉ 201.3 237.5 253.8 2.2 −63.0 (280.4)^(a) 35a, Cy,C₉ 195.3 236.6 254.6 2.5 −61.8 (282.5)^(a) 36, n-Non, C₉ 216.2 251.9268.1 1.1 −76.6^(c)  (94.6)^(a) 37, OMe, C₉ 173.0 211.4 226.9 7.3 −69.0111.45 — = Data not taken. ^(a)Cone-and-plate viscosity measurement incentiPoise (cP); KV not taken. The 20° C. cone-and-plate viscosity forDINP = 99.2 cP compared to 96.81 mm²/sec for 20° C. KV viscosity.^(b)Large exotherm, −57.0° C.; small exotherm, −36.6° C., strong meltingtransition, −17.5° C.; seen in both 1^(st) and 2^(nd) heats. ^(c)Veryweak; strong melting transition; −8.0° C.

The data in Table 12 show that, indeed, addition of higher carbon number(≧C₄) alkyl group substituents to the aromatic ring, with the use of C₉alcohols, resulted in a decrease in volatility compared to analogousplasticizers with smaller substituents (all of the compounds in Table 12show 220° C. weight losses of less than 9%, which is close to the weightloss of DINP). The viscosity remains within the target range except forthe sample derived from a cyclohexylbenzene substrate.

The use of naphthalenes, alkyl naphthalenes, and partly hydrogenated(alkyl)naphthalenes (tetralins), as more stable aromatics towards acidcatalysis, can also be used as a technique to improve plasticizerperformance, particularly to decrease volatility without increasing thecomplexity of the manufacturing process through aromatic alkylation(equation 7, below).

Example 38A Synthesis of 4-(1-Naphthyl)-4-oxobutanoic Acid by Acylationof Naphthalene with Succinic Anhydride

80 g (0.624 mol) of naphthalene, 20 gm (0.2 mol) of succinic anhydride,and 150 mL of nitrobenzene were placed into a 2 liter round bottom flaskequipped with an addition funnel, thermometer, mechanical stirrer andnitrogen purge. 55 g (0.41 mol) of aluminum chloride dissolved into 250mL nitrobenzene were added dropwise at 25° C. The temperature rose to31° C. during the addition. After addition the solution was poured intoa 2 liter beaker containing 100 mL HCl, 500 mL water, and 1000 mL ice.The mixture was stirred and the bottom layer was separated and placedinto a round bottom flask. The flask was placed on a Kugelrohrdistillation apparatus where the unreacted naphthalene and nitrobenzenewere removed. The residue was dissolved into 500 mL of 5% aqueous KOH.100 mL HCl was added to the KOH solution to precipitate the product. Theproduct was dissolved into chloroform and dried over MgSO₄ thenfiltered. The chloroform was removed under vacuum. The residue wasdissolved into hot benzene; upon cooling the product,4-(1-naphthyl)-4-oxobutanoic acid, crystallized out (weight ofcrystals=14.9 g).

Example 38B Synthesis of Oxo-C₁₀ Ester of 4-(1-Naphthyl)-4-oxobutanoicAcid

Into a 4-necked-250 mL round bottom flask equipped with an air stirrer,nitrogen inductor, thermometer, and chilled water cooled condenser wereadded 4-(1-naphthyl)-4-oxobutanoic acid (Example 38A, 16.0 g, 0.0555mol), OXO—C₁₀ alcohols (26.4 g, 0.1666 mol), and xylenes (46.9 g, 0.44mol). The reaction mixture was heated at 150-157° C. for 16 hours. Theexcess alcohols and xylenes were removed by vacuum distillation to 0.10mm. The crude product was treated with charcoal (decolorizing) withmagnetic stirring at room temperature for 2 hours, then filtered twice.The product remained colored with an orange color, and was found to be95.1% pure by GC analysis. The properties of the neat ester (95.1%purity by GC) are summarized in Table 13.

Example 39A Synthesis of4-Oxo-4-(5,6,7,8-tetrahydronaphthalen-1-yl)butanoic Acid by Acylation ofTetralin with Succinic Anhydride

In a 2 liter round bottom flask fitted with a mechanical stirrer,thermometer, condenser and nitrogen purge was added 150 gm (1.13 moles)of 1,2,3,4-tetrahydronaphthalene (tetralin). 75 gm (0.75 moles) succinicanhydride, and 750 mL benzene. A flask containing 203 gm (1.52 moles)aluminum chloride was attached to a flexible tube then attached to thereaction flask. The solid was poured, in batches, into the reactionflask over a period of 15 minutes. The temperature rose to 45° C. Afteraddition the mixture was heated at reflux for 3 hours. The solution wascooled to room temperature then poured into a 4 liter beaker containing2 liters of ice, 1 liter of distilled water and 200 mL of concentratedaqueous hydrochloric acid. A white precipitate formed, which wasisolated by filtration. The solid was dissolved into chloroform. Thechloroform solution was dried over magnesium sulfate, then filtered, andthe chloroform was removed from the filtrate on a rotary evaporator. Thecrude residual material was dissolved into 500 mL benzene at 75° C. Thesolution was cooled to room temperature to crystallize the product.Product yield: 145.5 gm (0.63 moles, 86%). GC-FIMS: ml/232 (M⁺, calcd.232.11). ¹³C NMR analysis indicated a 97:3 mixture of4-oxo-4-(5,6,7,8-tetrahydronaphthalen-1-yl)butanoic acid and4-oxo-4-(5,6,7,8-tetrahydronaphthalen-2-yl)butanoic acid.

Example 39B Repeat Synthesis of4-Oxo-4-(5,6,7,8-tetrahydronaphthalen-1-yl) butanoic Acid by Acylationof Tetralin with Succinic Anhydride

100 g (0.76 mol) of tetralin, 50 g (0.2 mol) of succinic anhydride, and500 mL of benzene were placed into a 1 liter round bottom flask equippedwith an addition funnel, thermometer, mechanical stirrer and nitrogenpurge. A flask containing 134 g (1.0 mol) of aluminum chloride wasattached to the reaction flask using a flexible tube. The solid wasslowly added to the flask at 25° C. over a period of ten minutes. Thetemperature rose to 40° C. during addition. After addition the solutionwas heated and refluxed for 3 hours. The solution was cooled, thenpoured into a 2 liter beaker containing 100 mL aqueous HCl, 500 mLwater, and 1000 mL ice. A white precipitate formed, which was collectedby filtration. The white solid was dissolved into chloroform and driedover MgSO₄, then filtered. The chloroform was removed from the filtrateunder vacuum. The residue was dissolved into 200 mL hot benzene, uponcooling, the product,4-oxo-4-(5,6,7,8-tetrahydronaphthalen-1-yl)butanoic acid, crystallizedout (weight of crystals=64.8 g). ¹³C NMR analysis indicated a similarisomer distribution to Example 39A (97:3).

Example 39C Synthesis of Oxo-C₁₀ Ester of4-Oxo-4-(5,6,7,8-tetrahydronaphthalen-1-yl)butanoic Acid

Into a 4-necked-1000 mL round bottom flask equipped with an air stirrer,nitrogen inductor, thermometer, and chilled water cooled condenser wereadded 4-(5,6,7,8-tetrahydronaphthyl)-4-oxobutanoic acid (Examples 39A/B,122.6 g, 0.5278 mol), OXO—C₁₋₁₀ alcohols (297.2 g, 1.88 mol), andtoluene (106.2 g, 1.153 mol). The reaction mixture was heated at150-159° C. for 14 hours. The excess alcohols and toluene were removedby vacuum distillation to 0.10 mm. The crude product was treated withcharcoal (decolorizing) with magnetic stirring at room temperature for 2hours, then filtered twice. The product remained yellow and was found tobe 97.9% pure by GC analysis. The properties of the neat ester, assumedto contain 3% of the 2-yl isomer (97.97% purity by GC), are summarizedin Table 13.

TABLE 13 TGA 1% TGA 5% TGA 10% TGA Wt Loss Wt Loss Wt Loss Wt Loss, DSCT_(g) Viscosity Ex. No., Structure (° C.) (° C.) (° C.) 220° C. (%) (°C.) (20° C., cP)^(a) 38B, C₁₀ ester of 4-(1-naphthyl)-4- 188.1 233.5252.2 2.9 −62.6 248.95 oxobutanoic acid 39C, C10 ester of4-oxo-4-(5,6,7,8- 191.7 229.4 246.2 3.3 −63.7  80.55tetrahydronaphthalen-1-yl)butanoic acid w/3% of 2-yl isomer (97.95%)^(a)Cone-and-plate (Anton Paar) viscosity.

The data in Table 13 show that, indeed, use of naphthalene- ortetrahydronaphthalene-based aromatics provides plasticizers withexcellent volatility, even without the necessity of appending alkylsubstituents from the ring(s). Increases in viscosity seen fornaphthalene-based esters can be corrected by use of a more flexibletetrahydronaphthalene (tetralin) substrate.

Table 14 shows the calculated solubility parameters of the estersprepared in Examples 38B and 39C versus diisononyl phthalate (DINP). Thedata show that the esters have similar solubility parameters to DINP.

TABLE 14 Solubility Plasticizer Parameter DINP 8.767578947 38B, C₁₀ester of 4-(1-naphthyl)-4-oxobutanoic acid 8.656306849 39C, C₁₀ ester of4-oxo-4-(5,6,7,8-H₄-naphthalen-1- 8.804591304 yl)butanoic acid

Example 40 Hydrolytic Stability Comparison Between OXO—C₉Benzoylbenzoate and Benzoylpropionate Esters and DINP

A 120 mL glass Parr reactor was charged with 25 grams of a 0.05N HClsolution plus 75 grams of either the OXO—C₉ benzoylbenzoate esterprepared in Example 3, the OXO—C₉ benzoylpropionate ester prepared inExample 18, or the commercial plasticizer DINP (diisononyl phthalate).The mixture was stirred for 33 days at 91-104° C. with GC samplingthroughout the heating period to quantify the amount of triglyceridehydrolyzed to diglyceride or other byproducts (“% TG conversion”). Dataare shown in FIG. 1.

Example 41 General Procedure for Plasticization of Poly(Vinyl Chloride)and Properties of Plasticized PVC Bars

A 5.85 g portion of the desired ester (or comparative commercialplasticizer DINP) was weighed into an Erlenmeyer flask which hadpreviously been rinsed with uninhibited tetrahydrofuran (THF) to removedust. An 0.82 g portion of a 70:30 by weight solid mixture of powderedDrapex® 6.8 (Crompton Corp.) and Mark® 4716 (Chemtura USA Corp.)stabilizers was added along with a stirbar. The solids were dissolved in117 mL uninhibited THF. Oxy Vinyls® 240F PVC (11.7 g) was added inpowdered form and the contents of the flask were stirred overnight atroom temperature until dissolution of the PVC was complete (a PVCsolution for preparation of an unplasticized comparative sample wasprepared using an identical amount of stabilizer, 100 mL solvent, and13.5 g PVC). The clear solution was poured evenly into a flat aluminumpaint can lid (previously rinsed with inhibitor-free THF to remove dust)of dimensions 7.5″ diameter and 0.5″ depth. The lid was placed into anoven at 60° C. for 2 hours with a moderate nitrogen purge. The pan wasremoved from the oven and allowed to cool for a 5 min period. Theresultant clear film was carefully peeled off of the aluminum, flippedover, and placed back evenly into the pan. The pan was then placed in avacuum oven at 70° C. overnight to remove residual THF. The dry,flexible film was carefully peeled away and exhibited no oiliness orinhomogeneity unless otherwise noted. The film was cut into small piecesto be used for preparation of test bars by compression molding (size ofpieces was similar to the hole dimensions of the mold plate). The filmpieces were stacked into the holes of a multi-hole steel mold plate,pre-heated to 170° C., having hole dimensions 20 mm×12.8 mm×1.8 mm (ASTMD1693-95 dimensions). The mold plate was pressed in a PHI companyQL-433-6-M2 model hydraulic press equipped with separate heating andcooling platforms. The upper and lower press plates were covered inTeflon®-coated aluminum foil and the following multistage pressprocedure was used at 170° C. with no release between stages: (1) 3minutes with 1-2 tons overpressure; (2) 1 minute at 10 tons; (3) 1minute at 15 tons; (4) 3 minutes at 30 tons; (5) release and 3 minutesin the cooling stage of the press (7° C.) at 30 tons. A knockout toolwas then used to remove the sample bars with minimal flexion. Typically,flexible bars were obtained which, when stored at room temperature,showed no oiliness or exudation several weeks after pressing unlessotherwise noted.

Two each of the sample bars were visually evaluated for appearance andclarity and further compared to identically prepared bars plasticizedwith DINP by placing the bars over a standard printed text initially andat the end of the test (typically around Day 21). The qualitative andrelative flexibility of the bars was also evaluated by hand. The variousbars were evaluated in different test batches; thus, a new DINP controlbar was included with each batch. The DINP bars were colorless. The barswere placed in aluminum pans which were then placed inside a glasscrystallization dish covered with a watch glass. The bars were allowedto sit under ambient conditions at room temperature for at least threeweeks and re-evaluated during and/or at the end of this aging period.Table 15 (where R is equivalent to R₁, and R′ is equivalent to R₂, asdescribed previously) presents appearance rankings and notes. The colorsof the bars generally reflected the colors of the neat plasticizers.

TABLE 15 Initial Example No. of Plasticizer Clarity Final Clarity Usedin Bar (A, R, R′)^(a) (Day)^(b) (Day) Notes on Bar at End of Test  1(Bz, H, C₆) — 1 (26) Somewhat stiff ~ DINP  2 (Bz, H, 2EH) 1 (0) 1 (38)V lt yellow, mod. stiff, < DINP  3 (Bz, H, C₉)  1 (14) — Sl. stiff.,sl. > DINP  4 (Bz, H, n-C₉) 1 (0) 1 (38) OK flex, sl. > DINP  5 (Bz, Me,C₅) — 1 (26) Quite stiff < DINP  6 (Bz, Me, C₆) — 1 (26) Quite stiff <DINP  7 (Bz, Me, 2EH) 1 (0) 1 (38) V. lt. orange, quite stiff < DINP  8(Bz, Me, C₉) — 1 (26) Quite stiff < DINP 17 (Pr, H, 2EH) 1 (0) 1 (38)Lt. yellow, excellent flex > DINP 18 (Pr, H, C₉)  1 (14) — Excell.flex, > DINP; yellow 19 (Pr, H, C₁₃)  1 (14) — Good flex, > DINP; yellow20 (Pr, H, n-C₉) 1 (0) 1 (38) Yellow, excellent flex 21 (Pr, Me, C₆) — 1(26) Extremely flexible 22 (Pr, Me, 2EH) 1 (0) 1 (38) Yellow, excellentflex > DINP 23 (Pr, Me, C₉) — 1 (26) Very flexible 24 (Pr, Me, C₁₃) — 1(26) Good flex 25 (Pr, op-2Me, C₉) 1 (0) 1.5 (38)   Yellow, v. goodflex > DINP 26, (Pr, op-2Me, C₁₀)  2 (13) 2 (23) Yellow, hazy, mod. goodflex > DINP 27 (Pr, mp-2Me, C₉) — 1 (21) V lt. yellow, good/v. good flex28 (Pr, mm-2Me, C₉) — 1.5 (21)   V. lt. yellow, sl. hazy, good/v. goodflex 29 (Pr, om-2Me, C₉) — 1 (21) Lt. yellow, good/v. good flex 30 (Pr,Et, C₉) 1 (7) 1 (39) Yellow, very good flex (Day 7) 31 (Pr, t-Bu, C₉)  1(13) 1 (23) Yellow, mod. stiff < DINP 32 (Pr, t-Bu, C₁₀) — 2 (21) Hazy,med/dark orange, sl. stiff 33 (Pr, s-Bu, C₉) 1 (9) 1 (27) Yellow, Okflex/sl. stiff, sl. < DINP 34 (Pr, n-Hx, C₉) 1 (7) 1 (39) Orange, OKflex > DINP (Day 39) 35 (Pr, Cy, C₉) 2.5 (13)  2.5 (23)   Yellow, hazy,somewhat stiff 35a (Pr, Cy, C₉) 1 (7) 1 (39) Yellow, mod. stiff, sl. <DINP (Day 7) 36 (Pr, n-Non, C₉) 1 (7) 1.5 (39)   Dark orange, stiff,flex ~DINP (Day 39) 37 (Pr, OMe, C₉)  2 (13) 2 (23) Yellow, hazy, goodflex 38B (Naphthyl Pr, C₁₀)  1 (13) 1 (41) Dark red, Ok/good flex(>DINP) 39C (H₄-Naphthyl Pr, C₁₀) 1 (4) 1 (35) Lt. orange, sl. stiff(sl. <DINP) DINP ctrl A^(c)  1 (14) — somewhat stiff DINP ctrl B^(c) — 1(26) Somewhat stiff DINP ctrl C^(c) 1 (0) 1 (38) Lt orange, OKflex/minorly stiff DINP ctrl D^(c)  1 (13) 1 (23) Somewhat stiff DINPctrl E^(c) — 1 (21) OK flex/sl. stiff DINP ctrl F^(c) 1 (9) 1 (27) OKflex DINP ctrl G^(c) 1 (7) 1 (39) OK flex/sl. Stiff DINP ctrl H^(c)  1(13) 1 (41) OK flex/sl. stiff DINP ctrl I^(c) 1 (4) 1 (35) OK flex/sl.stiff — Data not taken. ^(a)“A” commonly denotes the parent structure ofthe keto-acid chain spacer; Bz = benzoate; Pr = propionate. ^(b)1-5scale, 1 = no distortion, 5 = completely opaque; “Day” denotes daysafter pressing that the bar was evaluated; Day 0 = day of pressing.^(c)A = Ex. 3, 18, 19 test batch; B = Ex. 1, 5, 6, 8, 21, 23, 24 testbatch; C = Ex. 2, 4, 7, 17, 20, 22, 25 test batch; D = Ex. 26, 31, 35,37 test batch; E = 27, 28, 29, 32 test batch; F = Ex. 33 test batch; G =Ex. 30, 34, 35a, 36 test batch; H = Ex. 38B test batch; I = Ex. 39C testbatch.

Example 42 98° C. Weight Loss Study of Plasticized PVC Bars

Two each of the PVC sample bars prepared in Example 41 were placedseparately in aluminum weighing pans and placed inside a convection ovenat 98° C. Initial weight measurements of the hot bars and measurementstaken at specified time intervals were recorded and results wereaveraged between the bars. The averaged results are shown in Table 16(with R and R′ definitions as given in Table 15). Notes on theappearance and flexibility of the bars at the end of the test are alsogiven. The final color of the bars (even DINP control samples) variedbetween batches; gross comparisons only should be made between bars ofdifferent test batches.

TABLE 16 Ex. No. of Plasticizer Used in Bar Notes on Bar at (A, R,R’)^(a) Day 1 Day 2 Day 3 Day 7 Day 14 Day 21 End of Test  1 (Bz, H, C₆)0.2 0.45 0.75^(d) 0.99 2.19 3.21 Med orange, stiff  2 (Bz, H, 2EH) 0.180.18 — 0.89 1.11 1.25^(f) Orange, quite stiff < DINP^(f)  3 (Bz, H,C₉)0.40 0.46 0.81^(b) 0.79 1.37 1.79 Lt brown, somewhat stiff  4 (Bz, H,n-C9) 0.06 0.14 — 0.35 0.38 0.58^(j) Lt orange, OK flex < DINP, sl.stiff^(j)  5 (Bz, Me, C₅) 0.43 0.51 0.77^(d) 1.07 1.57 2.29 Med-ltorange, stiff  6 (Bz, Me, C₆) 0.32 0.29 0.68^(d) 0.80 1.27 1.77 Medorange, stiff  7 (Bz, Me, 2EH) 0.20 0.30 — 0.36 0.69 1.14^(h) Med ltorange, quite stiff < DINP^(h)  8 (Bz, Me, C₉) 0.23 0.23 0.20^(d) 0.280.51 0.54 Lt yellow, somewhat stiff, sl. < DINP 17 (Pr, H, 2EH) 0.490.66 — 3.50 6.10 7.12 Lt orange, v stiff, curled^(g) 18 (Pr, H, C₉) 0.240.30 0.70^(b) 0.71 1.35 1.79 Good flex > DINP, yellow 19 (Pr, H, C₁₃)0.21 0.17 0.36^(b) 0.34 0.49 0.53 Good flex > DINP, yellow 20 (Pr, H,n-C₉) 0.12 0.30 — 0.84 1.07 1.83^(k) Lt yellow, v good flex~DINP^(k) 21(Pr, Me, C₆) 0.57 1.03 3.74 4.13 6.23 8.34 Lt yellow, somewhat stiff,sl. < DINP, sl. curled 22 (Pr, Me, 2EH) 0.43 0.56 — 0.65 1.40 3.28^(i)Lt yellow, v good flex~DINP^(i) 23 (Pr, Me, C₉) 0.26 0.34 0.64^(d) 0.901.61 2.58 Med yellow, good flex > DINP, curled 24 (Pr, Me, C₁₃) 0.190.24 0.37^(d) 0.35 0.47 0.52 Med yellow, excel. flex > DINP., sl. curled25 (Pr, op-2Me, C₉) 0.24 0.38 — 0.57 1.60 2.07^(l) Yellow, v goodflex~DINP^(l) 26, (Pr, op-2Me, C₁₀) 0.20 — 0.71^(d) 0.78 0.84 1.16Yellow, hazy, curled, v good flex 27 (Pr, mp-2Me, C₉) — — 0.48^(c) 0.610.86 1.20 Lt orange, curled, excellent flex 28 (Pr, mm-2Me, C₉) — —0.71^(c) 0.87 1.51 2.13 Lt yellow, sl. hazy, OK/good flex 29 (Pr,om-2Me, C₉) — — 0.98^(c) 1.32 1.78 2.75 Lt yellow, curled, excellentflex

Example 43 70° C. Humid Aging Study of Plasticized PVC Bars

Using a standard one-hole office paper hole punch, holes were punched intwo each of the sample bars prepared in Example 41 ⅛″ from one end ofthe bar. The bars were hung in a glass pint jar (2 bars per jar) fittedwith a copper insert providing a stand and hook. The jar was filled with½″ of distilled water and the copper insert was adjusted so that thebottom of each bar was 1″ above the water level. The jar was sealed,placed in a 70° C. convection oven, and further sealed by windingTeflon® tape around the edge of the lid. After 21 days the jars wereremoved from the oven, allowed to cool for 20 minutes, opened, and theremoved bars were allowed to sit under ambient conditions in aluminumpans (with the bars propped at an angle to allow air flow on both faces)or hanging from the copper inserts for 1 week (until reversiblehumidity-induced opacity had disappeared). The bars were evaluatedvisually for clarity. All bars exhibited complete opacity during theduration of the test and for several days after removal from the oven.Results are shown in Table 17 (with R and R′ definitions as given inTable 15). Notes on the appearance and flexibility of the bars at theend of the test are also given.

TABLE 17 Example No. of Plasticizer Clarity (Days Used in Bar (A, R,R′)^(a) Ambient Aging) Notes on Bar at End of Test  1 (Bz, H, C₆) 1 (20)OK flex  2 (Bz, H, 2EH) 3 (28) Oily, sticky, hazy, mod. stiff, whitespots  3 (Bz, H, C₉) 1 (14) Somewhat stiff < DINP, some opaque spots  4(Bz, H, n-C₉) 2.5 (28)   OK flex/sl.stiff, many white spots, oily,sticky  5 (Bz, Me, C₅) 1.5 (20)   Stiff  6 (Bz, Me, C₆) 1.5 (20)  Fairly stiff, maybe sl. sticky  7 (Bz, Me, 2EH) 1 (28) Somewhat stiff,few white spots  8 (Bz, Me, C₉) 1 (20) Fairly stiff 17 (Pr, H, 2EH) 1(28) Excellent flex, few white spots 18 (Pr, H, C₉) 1 (14) Extr. goodflex, >>DINP 19 (Pr, H, C₁₃) 1 (14) Good flex > DINP 20 (Pr, H, n-C₉) 1(28) Excellent flex 21 (Pr, Me, C₆) 1 (20) Excellent flex, quick returnto clarity 22 (Pr, Me, 2EH) 1 (28) Excellent flex 23 (Pr, Me, C₉) 1 (20)Excellent flex, quick return to clarity 24 (Pr, Me, C₁₃) 1 (20) V goodflex, quick return to clarity 25 (Pr, op-2Me, C₉) 1.5 (28)   V goodflex, curled 26, (Pr, op-2Me, C₁₀) 1.5 (29)   OK flex/slightly stiff 27(Pr, mp-2Me, C₉) 1 (18) Excellent flex, white spots, minor oil 28 (Pr,mm-2Me, C₉) 1.5 (18)   Excellent flex, oily, many white spots 29 (Pr,om-2Me, C9) 1 (18) Excellent flex, very minor white spots/oil 30 (Pr,Et, C₉) 1 (18) Excellent flex, minor white spots/oil 31 (Pr, t-Bu, C₉)1.5 (29)   Good flex 32 (Pr, t-Bu, C₁₀) 2 (18) Orange, somewhat stiff,sl. < DINP 33 (Pr, s-Bu, C₉) 2 (30) Excellent flex, oily, hazy 34 (Pr,n-Hx, C₉) 1 (18) Good flex, no oil 35 (Pr, Cy, C₉) 3.5 (29)   Stiff 35a(Pr, Cy, C₉) 1 (18) Sl./mod. stiff (< DINP), minor white spots/oil 36(Pr, n-Non, C₉) 5 (18) Stiff, v. sl. fingerprints, no oil 37 (Pr, OMe,C₉) 1.5 (29)   Very good flex 38B (Naphthyl Pr, C₁₀) 1 (20) Good flex39C (H₄-Naphthyl Pr, C₁₀) 1 (14) Very good flex DINP ctrl A^(c) 1 (14)Slightly stiff DINP ctrl B^(c) 1.5 (20)   OK/good flex DINP ctrl C^(c) 1(28) Good flex DINP ctrl D^(c) 1 (29) OK flex/somewhat stiff DINP ctrlE^(c) 1 (18) V lt yellow, v minor white spots, OK flex/sl. stiff DINPctrl F^(c) 1 (30) OK flex, very minor oil, white spots, haze DINP ctrlG^(c) — — DINP ctrl H^(c) 1 (20) OK flex/sl stiff DINP ctrl I^(c) 1 (14)Very good flex — Data not taken. ^(a)“A” commonly denotes the parentstructure of the keto-acid chain spacer; Bz = benzoate; Pr = propionate.^(b)1-5 scale, 1 = no distortion, 5 = completely opaque. ^(c)See Table15.

Example 44 Weight Loss Study of Plasticized PVC Bars

A small portion of the plasticized sample bars prepared in Example 41,or alternately a small piece of thin material taken from the moldoverflow, were subjected to Thermogravimetric Analysis as previouslydescribed to evaluate plasticizer volatility in the formulated test barsfor selected samples. Results are shown in Table 18 (with A, R, and R′as defined earlier and in Table 15).

TABLE 18 % Weight Loss by TGA of Plasticized PVC Bars. TGA 1% TGA 5% TGA10% Ex. No. of Material Loss Loss Loss % Loss, Used in Bar (A, R, R′) (°C.) (° C.) (° C.) 220° C. DINP 204.6 247.4 257.6 1.8^(a)  3 (Bz, H,C₉)^(c) 203.6 240.5 251.2 2.0^(a,b)  3 (Bz, H, C₉), repeat^(d) 195.1237.7 248.3 2.6^(a) 18 (Pr, H, C₉)^(e) 173.2 210.6 233.9 6.9^(b) 18 (Pr,H, C₉), repeat^(f) 169.8 206.7 229.7 7.8^(a) 26 (Pr, op-2Me, C₁₀)^(g)187.6 228.9 246.3 3.7^(b) 26 (Pr, op-2Me, C₁₀), rpt^(h) 181.2 225.8248.1 4.2^(a) 31 (Pr, t-Bu, C₉)^(i) 190.7 235.1 248.8 2.7^(a) 31 (Pr,t-Bu, C₉), repeat^(j) 196.8 236.1 248.8 2.7^(a) 37 (Pr, OMe, C₉)^(k)189.1 229.5 247.0 3.3^(a), 4.7^(b) 37 (Pr, OMe, C₉), repeat^(l) 200.4238.5 248.7 2.3^(a) ^(a)Bar. ^(b)Circle of thin film (mold overflow).^(c)Bar/film aged 397/392 days. ^(d)Re-pressed bar aged 8 days. ^(e)Filmaged 392 days. ^(f)Re-pressed bar aged 9 days. ^(g)Film aged 225 days.^(h)Re-pressed bar aged 7 days, made using scaled up material asdescribed in Ex. 46. ^(i)Film aged 224 days. ^(j)Re-pressed bar aged 9days. ^(k)Bar/film aged 229/225 days. ^(l)Re-pressed bar aged 9 days.

Example 45 Demonstration of PVC Plasticization by Differential ScanningCalorimetry (DSC) and Dynamic Thermal Mechanical Analysis (DMTA)

Three-point bend Dynamic Mechanical Thermal Analysis (DMTA) with a TAInstruments DMA Q980 fitted with a liquid N₂ cooling accessory and athree-point bend clamp assembly was used to measure thethermo-mechanical performance of neat PVC and the PVC/plasticizer blendsample bars prepared in Example 41. Samples were loaded at roomtemperature and cooled to −60° C. or lower at a cooling rate of 3°C./min. After equilibration, a dynamic experiment was performed at onefrequency using the following conditions: 3° C./min heating rate, 1 Hzfrequency, 20 micrometer amplitude, 0.01 pre-load force, force track120%. Two or three bars of each sample were typically analyzed;numerical data was taken from the bar typically exhibiting the highestroom temperature storage modulus (the bar assumed to have the fewestdefects) unless another run was preferred for data quality. Glasstransition onset values were obtained by extrapolation of the tan deltacurve from the first deviation from linearity. The DMTA measurementgives storage modulus (elastic response modulus) and loss modulus(viscous response modulus); the ratio of loss to storage moduli at agiven temperature is tan delta. The beginning (onset) of the T_(g)(temperature of brittle-ductile transition) was obtained for each sampleby extrapolating a tangent from the steep inflection of the tan deltacurve and the first deviation of linearity from the baseline prior tothe beginning of the peak. Table 19 provides a number of DMTA parametersfor the bars (the temperature at which the storage modulus equals 100MPa was chosen to provide an arbitrary measure of the temperature atwhich the PVC loses a set amount of rigidity; too much loss of rigiditymay lead to processing complications for the PVC material). The flexibleuse temperature range of the samples was evaluated as the range betweenthe T_(g) onset and the temperature at which the storage modulus was 100MPa. A lowering and broadening of the glass transition for neat PVC wasobserved upon addition of the OXO ester plasticizers, indicatingplasticization. Plasticization (enhanced flexibility) was alsodemonstrated by lowering of the PVC room temperature storage modulus.Differential Scanning Calorimetry (DSC) was also performed on thecompression-molded sample bars (−90° C. to 100-170° C. at 10° C./min).Small portions of the sample bars (˜5-7 mg) were cut for analysis,making only vertical cuts perpendicular to the largest surface of thebar to preserve the upper and lower compression molding “skins”; thepieces were then placed in the DSC pans so that the upper and lower“skin” surfaces contacted the bottom and top of the pan. Alternately,pieces of leftover thin film were used. Results are summarized in Table19 (with A, R, and R′ as defined earlier and in Table 15); lowering andbroadening of the glass transition for neat PVC indicates plasticizationby the OXO-esters (for aid in calculating the numerical values of thesebroad transitions, the DSC curve for each plasticized bar was overlaidwith the analogous DMTA curve for guidance about the proper temperatureregions for the onset, midpoint, and end of T_(g)).

TABLE 19 DMTA and DSC Thermal Parameters for Plasticized PVC Bars Tan ΔTan 25° C. Temp. of Flex. DSC DSC DSC T_(m) Max Ex. No. of MaterialT_(g) Δ St. 100 MPa Use T_(g) T_(g) T_(g) (° C.), Used in Bar Onset PkMod. St. Mod. Rge Onset Midpt End ΔH_(f) (A, R, R’) (° C.) (° C.) (MPa)(° C.) (° C.)^(a) (° C.) (° C.) (° C.) (J/g)^(b) DINP −37.6 17.1 48.616.9 54.5 −37.8 −24.8 −12.2 N/A^(d)  3 (Bz, H, C₉)^(c) — — — — — −13.9−0.3 13.4 60.9,  N/A^(e)  3 (Bz, H, C₉), rpt^(f) −18.5 23.6 42.6 18.837.3 −15.8 −0.3 15.4 56.1,   0.56 18 (Pr, H, C₉)^(g) — — — — — −50.1−34.9 −19.9 64.2,  N/A 18 (Pr, H, C₉), rpt^(h) −41.8 5.9 12.2 4.3 46.1−42.4 −19.0 4.3 55.9    0.86 26 (Pr, op-2Me, C₁₀)^(i) — — — — — −48.8−30.0 −11.1 62.9,   1.43 26 (Pr, op-2Me, C₁₀), −45.4 23.5 85.5 23.6 69.0−29.0 −7.2 14.6 54.3,  rpt^(j)  1.06 31 (Pr, t-Bu, C₉)^(k) — — — — —−39.5 −25.9 −12.5 61.2,   1.28 31 (Pr, t-Bu, C₉), rpt^(l) −24.5 32.8117.5 26.4 50.9 −31.0 −10.6 9.8 55.9,   0.79 37 (Pr, OMe, C₉)^(m) — — —— — −30.6 −12.8 5.0 62.2,   2.03 37 (Pr, OMe, C₉), rpt^(n) −37.2 9.117.4 8.1 45.3 −40.4 −21.3 −2.2 56.1,   0.57 None^(c) 44.0 61.1 1433 57.113.1 44.5 46.4 48.9 N/A N/A = Not analyzed. ^(a)Difference between DMTAtemperature of 100 MPa storage modulus and onset of T_(g). ^(b)Somesample bars showed a weak melting point (T_(m)) from the crystallineportion of PVC. Often this weak transition was not specificallyanalyzed, but data is given here in instances where it was recorded.^(c)Neat PVC, no plasticizer used. ^(d)Very small. ^(e)Bar, aged 399days; 2^(nd) small endotherm peak at 93.7° C. ^(f)Remade bar (DMTA) andfilm (DSC), aged 20/9 (DMTA/DSC) days. ^(g)Bar, aged 399 days; 2^(nd)small endotherm peak at 89.9° C. ^(h)Remade bar (DMTA) and film (DSC),aged 15/9 (DMTA/DSC) days. ^(i)Bar, aged 232 days. ^(j)Remade bar (DMTA)and film (DSC), aged 8/7 (DMTA/DSC) days. ^(k)Bar, aged 231 days. 2^(nd)small endotherm peak at 87.4. ^(l)Remade bar (DMTA) and film (DSC), aged15/9 (DMTA/DSC) days. ^(m)Bar, aged 231 days. ^(n)Remade bar (DMTA) andfilm (DSC), aged 17/9 (DMTA/DSC) days.

Example 46 Further Demonstration of PVC Plasticization with BenzoylPropionate OXO-Esters

Plasticized PVC samples containing the substituted benzoyl propionateOXO-esters of Examples 26, 31, and 37 (prepared similarly, but on largerscale) or DINP (as a comparative) were mixed at room temperature withmoderate stirring, then placed on a roll mill at 340° F. and milled for6 minutes. The flexible vinyl sheet was removed and compression moldedat 340° F. The samples had the following formulation: 100 phr OxyVinyls® 240 PVC resin; 50 phr OXO-ester or DINP; 3 phr epoxidizedsoybean oil; 2.5 phr Mark® 1221 Ca/Zn stabilizer; 0.25 phr stearic acid.Comparison of the data for the formulations is given in Table 20 (withA, R, and R′ as defined earlier and in Table 15). A ⅜″ Loop Test showedno changes (acceptable) for all samples. In a 100% Relative HumidityTest (70° C., 11 days), the samples containing DINP and the Ex. 37 (OMe)plasticizer showed a moderate change from original; each sample wassticky and had an opaque appearance. The sample containing the Ex. 31(t-Bu) plasticizer showed a slight change having some stickiness, butless opacity. The sample containing the Ex. 36 (op-2Me) plasticizer hadalmost no stickiness and minor changes in appearance.

TABLE 20 Properties of PVC Samples Plasticized With 50 phr BenzoylPropionate OXO-Esters Versus DINP Plasticizer Used in Formulation Ex. 26Ex. 31 Ex. 37 (A, R, R′) (Pr, op-2Me, C₁₀) (Pr, t-Bu, C₉) (Pr, OMe, C₉)DINP Original Mechanical Properties Shore A Hardness (15 sec.) 77.5 80.675.7 80.3 95% Confidence Interval 1.1 0.2 1.3 0.8 Shore D Hardness (15sec.) 22.7 23.2 20.1 22.7 95% Confidence Interval 0.3 0.4 0.4 0.4 100%Modulus Strength, psi 1648 1846 1575 1691 95% Confidence Interval 25 1725 13 Ultimate Tensile Strength, psi 3263 3316 3287 3267 95% ConfidenceInterval 62 158 66 48 Ultimate Elongation, % 341 342 338 367 95%Confidence Interval 11 21 9 17 Aged Mechanical Properties (7 days at100° C., AC/hour) Aged 100% Modulus Strength, psi N/A* 2299 2677 239095% Confidence Interval N/A* 879 54 31 Ultimate Tensile Strength, psi3812 3303 3531 3013 95% Confidence Interval 1369 205 40 57 UltimateElongation, % 9 129 294 267 95% Confidence Interval 10 29 14 14 WeightLoss, Wt % 18.1 13.3 10.0 7.0 95% Confidence Interval 0.51 0.47 0.390.45 Retained Properties (7 days at 100° C., AC/hour) Retained 100%Modulus Strength, % N/A* 125 170 141 95% Confidence Interval N/A* 1.40.6 0.4 Retained Tensile Strength, % 117 100 107 92 95% ConfidenceInterval 1.0 0.4 0.2 0.2 Retained Elongation, % 3 38 87 73 95%Confidence Interval 0.8 1.4 1.0 1.0 Carbon Volatility (24 hours at 70°C.) Mean (3 Specimens) 1.9 1.5 1.2 0.6 95% Confidence Interval 0.0 0.00.1 0.0 Low Temperature Clash Berg (T_(f)), ° C. −16.0 −12.0 −10.0 −21.095% Confidence Interval 1.3 1.3 1.5 0.9 QUV/Humid Aging (2 Wks/2 Wks)yellow yellow dark yellow v. good *Sample was too stiff to obtainresults.

The OXO-ester plasticizers of the present application find use in anumber of different polymers, such as vinyl chloride resins, polyesters,polyurethanes, ethylene-vinyl acetate copolymers, rubbers,poly(meth)acrylics and mixtures thereof.

Claims for PCT Filing:

1. A process for making non-phthalate plasticizers, comprising acylatingan aromatic compound with a succinic anhydride to form a keto-acid, andesterifying the keto-acid with C₄-C₁₃ OXO-alcohols to form a plasticizercompound.

2. The process of claim 1, wherein the aromatic compound is of theformula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether and wherein there may be 1 or2 R₁ groups present on the aromatic or saturated ring which may be thesame or different, and the plasticizer compound is of the formula:

wherein R₁ is as set forth above, R₂ is the alkyl residue of theOXO-alcohols, and R₃ is H or C₁-C₈ linear or branched alkyl group.

3. The process according to claim 1 or 2, wherein the acylation iscatalyzed by a heterogeneous catalyst, a mixed metal oxide or a Lewisacid.

4. The process according to any preceding claim, wherein the acylationis conducted using a stoichiometric amount of AlCl₃.

5. The process according to any preceding claim, further comprisinghydrogenating the keto-group(s) of the plasticizer compound to formalcohol groups, and esterifying the alcohol groups with C₄ to C₁₃ linearor OXO-acids.

6. The process according to any preceding claim, further comprisinghydrogenating one or more of the aromatic rings.

7. The process of any of claims 2-6, further comprising hydrogenatingthe keto-group(s) of the plasticizer compound to form alcohol groups,and esterifying the alcohol groups with C₄ to C₁₃ linear or OXO-acids toform plasticizer compounds of the formula:

wherein R₄ is the alkyl residue of said linear or OXO-acids.

8. A plasticizer compound of the formula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether, R₂ is the alkyl residue ofC₄ to C₁₃ OXO-alcohols and wherein there may be 1 or 2 R₁ groups presenton the aromatic or saturated ring which may be the same or different,and R₃ is H or C₁-C₈ linear or branched alkyl group.

9. A plasticizer compound of the formula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether, wherein there may be 1 or 2R₁ groups present on the aromatic or saturated ring which may be thesame or different, R₂ is the alkyl residue of C₄ to C₁₃ OXO-alcohols, R₃is H or C₁-C₈ linear or branched alkyl group, and R₄ is the alkylresidue of C₄ to C₁₃ linear or OXO-acids.

10. A composition comprising a polymer and a plasticizer of the formula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether, wherein there may be 1 or 2R₁ groups present on the aromatic or saturated ring which may be thesame or different, R₂ is the alkyl residue of C₄ to C₁₃ OXO-alcohols,and R₃ is H or C₁-C₈ linear or branched alkyl group.

11. A composition comprising a polymer and a plasticizer of the formula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether wherein there may be 1 or 2R₁ groups present on the aromatic or saturated ring which may be thesame or different, R₂ is the alkyl residue of C₄ to C₁₃ OXO-alcohols, R₃is H or C₁-C₈ linear or branched alkyl group, and R₄ is the alkylresidue of C₄ to C₁₃ linear or OXO-acids.

12. The composition of claims 10 or 11, wherein the polymer is selectedfrom the group consisting of vinyl chloride resins, polyesters,polyurethanes, ethylene-vinyl acetate copolymer, rubbers,poly(meth)acrylics and combinations thereof.

13. The composition of claim 12, wherein the polymer ispolyvinylchloride.

14. The composition of claim 10 or 11, wherein R₂ has an averagebranching of from 0.2 to 4.0 branches per group.

15. The composition of claim 11 or 14, wherein R₄ has an averagebranching of from 0.2 to 4.0 branches per group.

All patents and patent applications, test procedures (such as ASTMmethods, UL methods, and the like), and other documents cited herein arefully incorporated by reference to the extent such disclosure is notinconsistent with this invention and for all jurisdictions in which suchincorporation is permitted.

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that various othermodifications will be apparent to and can be readily made by thoseskilled in the art without departing from the spirit and scope of theinvention. Accordingly, it is not intended that the scope of the claimsappended hereto be limited to the examples and descriptions set forthherein but rather that the claims be construed as encompassing all thefeatures of patentable novelty which reside in the present invention,including all features which would be treated as equivalents thereof bythose skilled in the art to which the invention pertains. The inventionhas been described above with reference to numerous embodiments andspecific examples. Many variations will suggest themselves to thoseskilled in this art in light of the above-detailed description. All suchobvious variations are within the full intended scope of the appendedclaims.

What is claimed is:
 1. A plasticizer compound of the formula:

wherein R₁ is selected from the group consisting of H, C₁-C₉ linear orbranched alkyl, cycloalkyl, or C₁-C₄ ether, and wherein there may be 1or 2 R₁ groups present on the aromatic or saturated ring which may bethe same or different, R₂ is the alkyl residue of C₄ to C₁₃OXO-alcohols, R₃ is H or C₁-C₈ linear or branched alkyl group; and R₄ isthe alkyl residue of C₄ to C₁₃ linear or OXO-acids.
 2. The plasticizercompound of claim 1, wherein R₂ has an average branching of from 0.2 to4.0 branches per group.
 3. The plasticizer compound of claim 1, whereinR₄ has an average branching of from 0.2 to 4.0 branches per group. 4.The plasticizer compound of claim 1, wherein R₂ has an average branchingof from 0.2 to 4.0 branches per group and R₄ has an average branching offrom 0.2 to 4.0 branches per group.